Booster seat



FIG. 1 is a front side perspective view of the design;

FIG. 2 is a front view of the design;

FIG. 3 is a rear view of the design;

FIG. 4 is a left side view of the design;

FIG. 5 is a right side view of the design;

FIG. 6 is a top view of the design; and,

FIG. 7 is a bottom view of the design.

The broken lines throughout the figure views are for illustrative purposes only and form no part of the claimed design.

Any surfaces of the design not shown, including interior surfaces, form no part of the claimed invention. 

I claim the ornamental design for a booster seat, as shown and described. 